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These are things that I have heard time and time again, and you will too as you see patients on the wards or in clinics. This will even happen at the local restaurant or family gatherings. They are the words that are often a patient’s first volley into their hope for a fix. Those phrases, however, need to be fleshed out, parsed and hunted through. They mainly give you a sense that of visual unhappiness. Keep reading if you’d like to see some of the history points and questions you may ask to begin your hunt for an answer, or at least to know how worried you should be about the patient before you.

Go open ended right out of the box

Ask open ended questions

I usually strike an engaged posture and ask them what they mean by terrible vision. The conversation will go in a whole array of directions with that, but those directions are good, great even. After they have begun to explain their symptoms you can then cone down with more focused questions.

The following things are crucial to sort out as you listen and engage them.

Does having their glasses on make any difference?

Is the trouble with their near vision or far vision?

Is it there all of the time or just some time?

Does blinking make a difference?

Is it blurry like “looking through a shower curtain,” or dim “like someone turned the lights down”?

Both eyes or just one?

Is part of the vision missing? as in the top or bottom part? Left or right part?

It is not as crucial for the primary care provider to determine etiologies or to quantitate the visual level as in Snellen Acuity. It is more important that they are able to come to a conclusion on the urgency of a given situation. Does their care need moved to a specialist now or can it reasonably be delayed? That is part of this question. Also do they need to see an ophthalmologist or a neurologist? That is, are the symptoms consistent with an eye issue or a brain issue? [Read more…] about Terrible vision? What’s that mean to you?

Ants and their bad day

To make the slitlamp exam a thing you “get” let me pose a question to you: Have you ever used the sun and a magnifying glass in nefarious ways? Have you ever burned leaves of “popped” ants. Once when I was at the Wills Eye Course Dr. David Guyton brought this up during the optics review. He asked the large group of us if we knew why ants made that popping noise when you used the sun and a magnifying glass to heat them up. I think we all laughed that quiet nostalgic laugh.

Well, he told us the answer. He said that the heat makes their insides boil and eventually their exoskeleton ruptures with a pop! Somehow the audience found this satisfying, but maybe the ants don’t. I am not an ant, but I guess that is one of the ways an ant can have a bad day.

Now how do you do this?

Blurry except at focal point.

Well, it is not difficult. Look at YouTube and you will see kids posting and narrating this stuff. 1Moms, do you know what your kids are posting? So if you want the ant to pop or the leaf to burn you must make the focal point as small as possible. If you are too close or too far away the ant gets warm, but he does not pop.

A more normal use of that magnifying glass

Usually a magnifying glass magnifies. You would probably learn more by looking at the ant with that instrument rather than making him poof.

A slit lamp is very much like this magnifying glass with one major exception. You cannot set your patients on fire with the light though they may feel it is bright enough to pop their eye.

The point though is to put the focal point of the slit lamp on the various parts of the eye to make clinical observations. Look at the two dimensional view below and relate it to the three dimensional image above.

Sharp focus at the focal point

This two dimensional view is how magnifying glasses work AND it is how the slit lamp works. There is only a single point where the slit lamp provides sharp focus. That does not mean you will not see other structures, you will. Those other structures though will be blurry to some extent. The closer those other structures are to the focal length the more distinct they will be. This is important to understand because by that you will know which direction to move the slit lamp in order to visualize other structures. Look, now, at the figure below and click through it. Notice the manner in which the sharp focus “descends” into the eye.

Slitlamp exam schematic

Focus in front of eye

(all eye structures should be blurry with this focus)

Focus on cornea

(Could focus on anterior, middle or posterior cornea as well)

Focus in anterior chamber

(Could focus at various anterior chamber depths, e.g. to see cell/flare)

Focus on superior iris

(Could focus on temporal, nasal, inferior iris as well)

Focus in lens

(could focus at different layers in the lens)

Focus in anterior vitreous

(Structures anterior to vitreous focus will be blurry)

As the slit lamp moves closer to the eye the structure in focus will simultaneously be deeper. Using the slit lamp alone you will routinely be able to see structures as internal as the anterior vitreous. In most cases you will need to use a condensing lens, e.g. the 90D lens to see deeper structures, but that is for another lesson.

Now practice this with these questions…

If the iris is clear the cornea will be .

blurry

If the iris is clear the lens will be , but than the cornea.

a. blurry, b. clearer

To make the cornea clear I need to the slit lamp from the eye.

a. Pull, b. away

To make the lens clear I need to the slit lamp the eye.

a. push, b. toward

When the lens is clear the iris will be but than the cornea.

a. blurry, b. clearer / less blurry

If all the structures of the eye are blurry then I need to either the slit lamp the eye or the slit lamp from the eye.